What It Is
Loratadine belongs to a class of medicines called antihistamines, and like cetirizine, is part of a newer generation generally associated with less drowsiness than older antihistamines.
What It's Used For
Loratadine is generally used to relieve allergy symptoms, including sneezing, runny nose, itchy or watery eyes, and itching associated with hives or other allergic skin reactions.
How It Works
Loratadine works by blocking H1 histamine receptors, preventing histamine, a chemical released during allergic reactions, from binding to these receptors and triggering the symptoms typically associated with allergies. Because loratadine is formulated to cross into the brain less readily than many older antihistamines, it's generally associated with a lower likelihood of causing drowsiness while still effectively blocking histamine's action elsewhere in the body.
History and Regulatory Status
Loratadine was developed by an American pharmaceutical company and was approved for clinical use in the late 1980s and early 1990s, entering the market around a similar time to other newer-generation antihistamines. It became widely recognized for its once-daily dosing and reduced sedative effect compared to older antihistamines available at the time. Its patent protection expired in the early 2000s, after which it became widely available over the counter in many countries, and it remains one of the most commonly used allergy medicines globally.